ask my dearest teachers' help

I have no answers to the questions that I have looked up in the dictionary but cannot get. I only guess the answers but not sure, so I need your help , teachers. Thank you very much.
which expression doesn't match with each complete sentence and how to correct it .
1.We have to explain to you that__B___.
A.we have been heavily burdened with the cost on opening an L/C
B. it has tied up a great deal of our fund to open an L/C
C. establishment of an L/C has involved us in a lot of expenses
2. We know that__A_, but we believe your accommodation in this term is quite necessary for promotion of our business.
A.your customary procedure of payment is to do business on L/C
B.your usual practice of payment is to purchase goods by L/C
c.yourrule of payment is to deal withe your customers on the L/C basis
3. As to terms of payment, we agree to _A____ the value of your purchase.
A draw your attention to D/A at 60 days sight for
B. draw a draft on your at 60 days D/A for
C.drow on you at 60 days D/A against
D. draw D/A at 60 days sight against
4. We propose that we__A__.
A. remit you the whole amount of the goods by T/T
B. make remittance for the whole amount of the goods by telegraph
C. make payment for the whole amount of the goods by T/T
D. transfer the whole anount of the goods to us by telegrph
5.The shipment should be made __b___ August 9. ( can you tell me the difference between them)
6.Your claim on the shortage of weight _c___ to 3,980 kgs in all.
a. account b. accounts c. amounts

[Mister Micawber]

1. No, a letter of credit does not cost so much.
2. I think not, but we are starting to encounter typographical errors in your sentences, and because of the terminology used, it is important that the sentences be precise-- please check the originals for any question I am unsure of.
3. No, the collocation is 'draw against'.
4. No. They don't 'remit the goods'-- think who is paying whom... and by what method.
5. You didn't post the choices, so I don't know. Please be careful to proofread your messages before posting.
6. YES!

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